Anodizing rack



y 1962' w. J. SHARON ETAL 3,035,999

ANODIZING RACK Filed Aug. 7, 1959 1 INVENTOR W/L FRfD J SHARON M/TCH ELL L 07').

ATTORNEY moa xq J 5% United State The invention relates to a material handling rack and particularly pertains to a rack which may be used in anodizing treatments and similar electroplating processes.

In conventional manufacturing processes, it is customary when handling articles to be anodized to place the articles in tote pans or baskets after machining, place the article by hand upon an anodizing rack, anodize the article, remove the anodized article from the rack, and place in another tote pan. This process is obviously expensive due to the fact that the article is handled several times to permit anodizing.

The conventional anodizing rack is usually constructed from aluminum and during the anodizing of the articles, the rack also is anodized. As the anodized coating does not have sufficient conductivity to permit reuse of the rack, the rack must be stripped, e.g., dipped in a solution of phosphoric and chromic acids to remove the coating whereby the rack may once again be used for supporting articles. As the cleaning or stripping process erodes the rack and weakens the resiliency of the rack fingers, repeated stripping of the rack causes such de-' terioration thereof that the rack becomes unuseable after 25 or 30 cycles. It is imperative that the articles to be coated be firmly held by the rack as a shifting of the article on the rack during the anodizing treatment causes the article to burn which produces a defective coating. It is also important that the contact of the rack and article be at a minimum to insure a complete coating.

To minimize the described problems, it is an object of the invention to provide amaterial handling rack which can be loaded at the final machining operation, be employed in the anodizing treatment and may be used to store and transport the coated articles to final inspections and assembly operations, thereby eliminating special handling during the anodizing process.

Yet another object of the invention is to provide a material handling rack of lightweight material which may be used in anodizing treatment tanks yet is not materially affected itself to deleteriously affect the use of the rack through many coating cycles.

A further object of the invention is to provide a material handling rack which may be used in anodizing treatment wherein the articles to be coated are firmly gripped by insert fingers and wherein the resiliency, conductivity and efiiciency of the fingers is not materially affected by the anodizing process.

Another object of the invention is to provide a material handling rack for use in anodizing treatments wherein the racks may be stacked for concise arrangement, counting of the articles racked is simplified, and inspection of the coating is facilitated.

These and other objects of the invention arising from the details of an embodiment thereof will be apparent from the following description and accompanying drawings wherein:

FIG. 1 is a perspective view of a material handling rack in accord with the invention showing several articles to be anodized supported within the rack,

FIG. 2 is an end elevational view of the rack of the invention,

FIG. 3 is a sectional elevational view of one of the corner posts as taken along line III-III of FIG. 1, and

FIG. 4 is a sectional, elevational detail view of the insert fingers and the lateral ribs mounting the fingers.

atent Patented May 22, 1962 Referring to the drawings, the rack of the invention preferably takes a rectangular basket form having a lower rectangular frame 10 and an upper rectangular frame 12 maintained in spaced parallel relation by a plurality of vertical spacers 14 and corner posts 16. The lower frame 10 is filled with a plurality of lateral ribs 18 and a pair of longitudinal ribs 20 which provide the supporting structure for the insert fingers. Preferably the lower frame 10, upper frame 12, spacers 14, posts 16 and ribs 18 and 20 are formed from a single casting of aluminum alloy whereby a light, rigid, integral structure of high strength will be obtained. 'It will be appreciated, however, that the principles of the invention may be practiced in a fabricated rack of similar shape.

The lower frame 10 is of slightly less dimensions than the upper frame 12 and the lower longitudinal portions 22 of frame 10 project downwardly, FIG. 2, to serve as runners which support the rack when placed on a planar surface and aid in stacking, as will later be apparent. As will also be apparent from FIG. 1 and FIG. 2, the difference in sizes of frames 10 and 12 results in theinner edges of the vertical spacers 14 being inclined .and the spacers and corner posts 16 are located in the outer edge regions of the lower frame. 1

The articles 24, which are to be anodized, are individually supported within the rack upon pairs of insert fingers consisting of a straight finger 26 and a shaped finger 28. The fingers are spaced such that upon inserting an article 24 therebetween, the fingers will be biased apart and the resiliency of the fingers provides a gripping action. The fingers are of circular cross section and hence when supporting a tubular article such as 24, the finger 26 will have only a line contact within the bore of the article and the finger 28 engages the exterior of the surface at little more than point contact due to the offset portion 30 of the finger 28. This type of support minimizes defects in the coating due to the supporting elements, yet firmly supports the article to prevent shiftingof the article relative to the fingers. It will beappreciated that the particular shape of the fingers 26 and 28 will depend on the shape of the article to be supported and other configurations than those disclosed may be employed. However, the illustrated finger configuration has been found to be quite universal and acceptable for a wide range of tubular articles.

An important feature of the invention resides in the fact that the article supporting fingers are formed of a relatively inert material such as titanium. This feature is of critical importance in that by using titanium fingers, the fingers are not adversely affected to an appreciable degree during the anodizing of the articles 24, and hence it is not necessary to strip the rack after the anodizing treatment in the usual phosphoric and chromic acid bath to permit reuse of the rack. It is the stripping of conventional racks which adversely affects the resiliency of the fingers and erodes the fingers, necessitating scrapping the racks after 25 or 30 treatments. Titanium has proven satisfactory as fingers of this metal anodize slowly under normal anodizing treatments yet have adequate'resilient characteristics to firmly grip the articles to be coated, and has sufiicient electrical conductivity to properly conduct the anodizing voltages tothe articles 24.

Preferably, the insert fingers 26 and 28 are cast into the lateral ribs 18 during the initial casting of the rack.

To insure that the fingers are firmly embedded into the ribs 18 the lower end of the fingers is notched at 32 whereby the cast aluminum material will fill the notch and effectively anchor the fingers against rotational or axial movement.

To aid in stacking the racks, the corner posts 16 are provided with axial bores 34 at each end and a plug 36 having a conical head is inserted into the bore at the upper end of each post 16. A plug 38 provided with a conical recess is inserted into the'bore 34 at the lower rack to accurately locate and support the racks. It will also be noted that from the stacked racks, represented by dotted lines, that the portion 22 of the frame 19 is of such .length as to project into the plane of the frame 12 of the lower rack without interference therewith.

To best utilize the advantages of the rack of the inven tion, the articles 24 should be placed on the titanium fingers 26-28 at the final machining station or inspection station after the final machining operation. The racks are then transported to. the anodizing area and placed upon platforms which are connectedrto bus bars conducting the anodizing voltages. The anodizing platforms need only be of a width slightly greater than the width of the rack; however, by stacking several racks, a considerable number of parts may be treated at once. After the anodiziugtreatment, the racks are removed from the platform and the articles may be visually inspected for coating defects. The racks may then be transported to final inspection or packaging stations. It will thus be apparent that the rack of the invention eliminates any special article handling due to the anodizing treatment.

The number and location of theribs 18 and 20 and fingers 26 and 28 may be varied to suit the particular applicatiomand racks may be constructed having many fingers for supporting many small articles, or fewer fingers for holding large articles, By. supporting the coated articles in the disclosed manner, counting is simplitied and loss of articles into the anodizing tanks is reduced over conventional racks.

For electroplating applications the rack and corner post elements interposed between said frame portions and rib elements extending across said lower frame portion, insert fingers for supporting articles to be anodized mounted upon said rib elements and extending therefrom, and stacking means formed on said corner posts adapted to associate with similar means on like racks during stacking of such racks. p

2. A material handling rack as in claim '1 wherein said casting is of aluminum alloy and'said insert fingers are formed of titanium.

3. A material handling rack as in claim 2 wherein said insert fingers comprise a pair of cylindrical elements in relatively close spaced relation, one of said cylindrical elements having an offset portion directed toward the other element.

4. A material handling basket as in claim 1 wherein said stacking means comprises a plug having a conical projection afiixed to one end of said corner posts and a plug having a conical recess afilxed to the other end of said corner posts.

5. A'material handling rack for use in anodizing treat ments comprising, in combination, a lower frame member having transversely extendingribs, an upper open frame member held inp'arallel spaced relation to said lower frame member by spacer elements interposed therebetween, finger means mounted onand extending upwardly from said ribs and adapted to support articles being treated, and vertically spaced and aligned first and second mating stacking means carried by said upper and lower frame members, respectively, and adapted to ac commodate vertical stacking of a plurality of said racks.

6. Subject matter of claim 5 wherein one of said stacking means includes a plurality 'ofprojections and the other a plurality of recesses adapted to mate with said projections.

References Cited in the file of this patent UNITED STATES PATENTS Mann Dec. 26, 1933 2,331,071 Halvorsen Oct. 5, 1943 2,760,929 Sheparclet al.' Aug.v 28, 1956 2,852,410 Brewer Sept. 16, 1958' 2,865,832 Pitzer Dec. 23, 19-58 

1. A MATERIAL HANDLING RACK FOR USE IN ANODIZING TREATMENTS COMPRISING A CASTING HAVING AN UPPER RECTANGULAR FRAME PORTION, A LOWER RECTANGULAR FRAME PORTION, SPACER AND CORNER POST ELEMENTS INTERPOSED BETWEEN SAID FRAME PORTIONS AND RIB ELEMENTS EXTENDING ACROSS SAID LOWER FRAME PORTION, INSERT FINGERS FOR SUPPORTING ARTICLES TO BE 